Is 4 OZ Allowed On Plane? (Beat The TSA Rules)

If you are already familiar with the airlines liquid rules, you know that there are limits to the amount of liquids you can bring on board the airplane.

Within and to The US airports,  the TSA (Transportation Security Administration) regulates the amount and the items you can and can’t bring in both carry-on and checked luggage.

Therefore, you will need to adhere to their safety regulations.

In addition, they have a dedicated section for liquids on their website ( the TSA 3-1-1 liquid rule ), which states that each passenger is allowed to bring only 3.4 oz / 100 ml of liquids for each container, inside a quart sized bag.

However, many travelers still want to take more and wonder what will happen if the containers are slightly over the allowed size; and if a 4 ounces bottle can pass through the security checkpoint.

Let us find out together what the TSA liquid rules are and what will happen if you want to bring a 4 oz bottle to the airplane.

Empty drink bottles

How Many Ounces Of Liquids The TSA Allows And What Is Considered a Liquid?

The TSA stated on its website that aerosols, liquids and pasts are permitted in carry-on luggage in limited quantities.

The 3-1-1 Rule stands for 3 ounces, 1 passenger, 1 quart-sized bag, and the total of liquids that are allowed in the carry on is defined by the quart size bag, and mostly it is around 34 oz or / 1000 ml.  

Any item that you can squeeze, smear, pump, spread, spray, or spill it then it will count as a liquid. and each bottle of liquid need to be 3.4oz / 10ml or less.

Here are some items that need to be no more than 3.4 oz / 100 ml and should be placed in a quart size bag.

Why Can You Only Take 3.4 Oz Bottles on a Plane?

The airport security does not have any intentions for banning items on board the airplane; but rather for the safety of the passengers and the aircraft they changed their rules.

There are no restrictions on liquids before, but nowadays most airports apply the same liquid limits, after some bad guys wanted to sneak explosives through the security checkpoint in 2006 at the UK Heathrow airport.

Therefore, the air travel authorities tend to decrease the allowable quantity to only 3.4 oz / 100 ml as a maximum of liquids that will not pose any harm or threat for the safety of the airplanes

So is 4 oz allowed on plane?

The TSA and most airport securities allow only liquids containers no more than 3.4 / 100 ml in carry-on luggage.

However; there are some exceptions to the 3-1-1 rule when you can bring quantities of liquids larger than 3.4 oz / 100 ml and you can take you can take 4 oz, 5 oz or even 6 oz bottles, when traveling with a baby (Breast milk and formula for example) or when traveling with liquid medications.

AskTSA answer a user question on twitter
Credit Twitter

Rather than you can place either large liquid bottles in your checked bag or refill them in small containers.

What Happens If You Bring Containers Larger Than 3.4 Oz /100 ml?

I don’t think you can sneak a 4 oz bottle inside carry-on luggage, even if it is not labeled or it has the same shape as a 3.4 oz bottle.

The airport security officers are trained and alert with these items, they will figure out as soon as they saw that bottle, and mostly the little cute bottle will end in the wastebasket.

It is better to take refillable bottles and small containers to avoid any inconvenience, or arguing with the airport security agents.

Refillable bottles are handy and most travelers use them to travel with toiletries and other liquids. They come in beautiful shapes and sizes and they will help you take what you will need during your trip.

If it happens and you show up to the airport with a larger size of liquid, it is better to transfer them to your checked luggage before you proceed to the security checkpoint.

What Does a 3.4 oz Bottle Look like?

Here is an example of a 3.4 oz bottle.

Small 3.4 oz / 1000 ml bottles are everywhere in our homes, you can find them in perfumes, shampoo and even in food .

Moreover, most companies are manufacturing travel sized products.

For example if you search for travel size shampoo on Amazon, you will be loaded by tons of 3.4 oz shampoo bottles and you will not need to refill a bottle for your next trip.

Can You Take 4 oz Bottles On International Flights?

Taking liquids on international flights have almost the same rules as traveling domestically.

You will need to adhere to the airline’s liquid limits.

I recommend having a look at your airline luggage rules, that way you will have a clear idea about what they allow.

For example if you are traveling from the US to Canada or to the UK, you still need to take only 3.4 oz / 100 ml because you will go through the TSA and the same rules are applied at the Canadian and UK airports.

I don’t think it is a good idea to bring liquids in carry-on luggage on international flights, even if you purchase them at the duty free shopping.

You can notice that the TSA here stated that “Duty-free liquids must be packed in a transparent, secure, tamper-evident bag by the retailer & they show signs of tampering when presented for screening.”

But still many travelers complained that their liquids had been confiscated.

AskTSA answer on Twitter
Credit Twitter

So the TSA recommends placing any larger liquids in checked luggage, becsaue the TSA or airport agents in general has always the final decision if an item can be allowed or not through the security checkpoint.

A user asked the TSA on Twitter about liquid
Credit Twitter

What Items Are Not Allowed Even If They are In 3.4 oz Bottles?

Even if you want to stay within the liquid limits there are still some items that you cannot bring on board the airplane.

Here are some examples that are banned entirely from airplanes.

ItemsCarry-on Checked bag
Alcoholic beverages over 140 proofNoNo
Aerosols that  are not considered toiletries or makeupNoNo
Any other flammable liquids, like Gas, Fuel ect..NoNo
Toxic liquidsNoNo
Bear sprayNoNo
Spray PaintNoNo

Final Thoughts

In general, liquids in carry-on luggage should be no more than 3.4 oz / 100 ml, except when traveling with infants, medication or purchased items at duty free shopping (on international flights).

In that case, you can bring 4 oz bottles or more without any problem.

If you want to know more about liquids in checked luggage, you can check out this detailed post.

We hope this helps.

Happy travels